As part of the tiered compilation work for Mustang, the HotSpot client compiler needs to be enhanced to update the methodDataOop profiling counters used by the server compiler to generate higher-quality code.

I didn't test 16bit games yet (The game Snow Bros. seemed to benefit much more from 1.6 client in a previous snapshot).Previously I noted that this game ran about as fast as MAME when using 1.6 client, but I forgot to turn off the debugger in MAME, doh!If you compare with MAME, you can see java has got a long way to go until it reaches C speed for this kind of thing...The CPU emulators in JEmu2 are highly optimized as well as the rendering stuff. Sometimes even more so than in MAME, but I guess java was not made for things like this...

Note that the SF2 hw doesn't really run at 12Mhz, but the version of MAME I used had it wrong and set the clock to 12Mhz instead of 8Mhz. In the online version, SF2 runs at 8Mhz (the correct speed) and runs on my machine at about 135fps on the server VM. For the sake of this test I temporarily set it to 12Mhz as well.Another note should be that the version I used for MAME uses an asm MC68000 core which is much faster than its portable C core.Last but not least, the video emulation in JEmu2 of this hardware driver is not based on MAME and I suspect that it's not very optimized for speed; all graphics are decoded and rendered in real time without any caching or anything at all.Given all that, java performs pretty well here!

The benches were run without the "large" flag and for a minimum period of 10 sec. A longer time, or, -Xcomp flag didn't make any significant difference. The 1.6.0 server bench was ran without the -Xcomp flag (more on that later):

Nice speed-ups with 1.6.0 ! The sparse matrix multiplication kernel with the server option turns out timings that seem awry. Don't know what the reason is - 2D arrays ?? With the system overclocked, both client and server exhibit identical speedups that match the CPU speedup.

Azeem ! Is the SSE2 support for AMD64 fully complete in the compiler ? IIRC, not long ago, you said something to the effect that it wasn't (in the server compiler).

And on using the -Xcomp option in conjunction with the -server option in 1.6.0, there is a gross degradation in performance as below:

Should there be a performance enhancement with 1.6.0-rc-b60 over 1.5.0_04 for, in particular, int mult and div ? Seems quite insignificant.

FWIW, the benchmarks with C version of SciMark2 (equivalent to the Java version *I suppose* and haven't checked) with VC++6.0/SP6 with the following makefile flags (AMD64 system as described earlier with CPU @ 1.8GHz):CC = cl -Za -W3CFLAGS = -nologo -O2x /G6$(CC) $(CFLAGS) scimark2.obj $(OBJS)

Uninstalled b60 again. It's giving me unknown host Exceptions with Webstart where definitely are none and it has some problems with the applets from this site: http://www.tokima.com

Could you please post the stack trace for one of these UnknownHostExceptions? I recently tracked down a problem with a change in Java Web Start in a relatively early Mustang build which was causing problems like this and would like to know if the problem you're seeing is related. FYI, please see bugs 6228306, 6346071 and related bugs. There is currently no bug filed against Java Web Start because of the regressions caused by 6228306 though I'm still pushing the deployment team to back out that fix.

I've been in discussions with the deployment team about DNS problems and one of the members of Sun's Java SE networking team found the root cause of some of these applet-related DNS problems. They are unrelated to Java and are caused by installing MSN Messenger 7.5.

Quote

When installing [MSN Messenger 7.5] [it] changes [a] registry entry: HKLM\System\CurrentControlSet\Services\TCPIP\Parameters\DatabasePath from REG_EXPAND_SZ to REG_SZ which causes it to fail to expand %SystemRoot%, therefore breaking the path. Changing the key back to REG_EXPAND_SZ solves the problem on the machine, but to do so you have to delete the entry and re-create it!

If anybody is experiencing DNS-related issues with Java, please look into this workaround and see if it's what you're experiencing. We'll escalate this issue with Microsoft.

Is it possible that this UnknownHostException is related to a setup issue? Has anything on the system been changed since the last mustang version worked?What was the last version that worked successfully?

Can we get some more information about the setup on your machine: - is ipv6 enabled? - Do you need a proxy to access the internet? - is your machine setup to use DNS for name resolution?

Would it be possible to run the following code passing it the hostname that is unresolvable:

"No, the stack allocation of non-escaping objects is planned for the release after Mustang. Depending on the performance benefit it gives and the size and complexity of the changes required, it could be eventually backported to a future Mustang update release, but there are no current plans to do so."

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